Gas generator

Abstract

To obtain a gas generator which achieves cost reduction by achieving reduction of the weight and simplification of components, compared to conventional gas generators.SOLUTION: A gas generator 100 has an outer shape of an elongated substantially columnar shape and includes: a housing 10; a holder 20 attached to one opening end of the housing 10; an igniter 50 which is held by the holder 20 and ignites the gas generator 31; a cup member 32; and a filter 41. The cup member 32 is installed within the housing 10 with one end of the filter 41 inserted into the cup member 32, and then a diameter is reduced to the radial inner side at a portion, which corresponds to a part of a peripheral surface of a cylindrical part 32a of the cup member 32, of a peripheral wall 10b of the housing 10 to form an annular groove part 32a1 and an annular groove part 41b and thereby crimp the cup member 32 to the housing 10 and the filter 41.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gas generator incorporated in an airbag device as an occupant protection device mounted on an automobile or the like, and more particularly to a so-called cylinder-type gas generator having a long cylindrical shape.

Background Art

[0002] In a cylinder-type gas generator, the long cylindrical housing generally has a configuration in which one end is closed by a closing member and the other end is closed by a holder having an ignition part (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, for the gas generators represented by the above patent documents, further weight reduction and cost reduction by simplifying parts are desired.

[0005] Therefore, an object of the present invention is to provide a gas generator that has been reduced in weight and cost by simplifying parts as compared with the prior art.

Means for Solving the Problems

[0006] (1) The gas generator of the present invention is loaded with a gas generating agent that generates gas by combustion, includes a filter through which the gas passes inside, and has a gas ejection port for ejecting the gas formed at a position corresponding to the filter in a long cylindrical housing, an igniter capable of igniting and burning the gas generating agent, a holder that holds a part of the igniter and is fixed to one end portion in the axial direction of the housing, a closing member fixed to the other end portion in the axial direction of the housing, and a positioning member that contacts the filter in the housing and can be used to determine the position of the filter. The positioning member has at least a cylindrical portion having a shape following the inner wall shape of the housing, and the cylindrical portion is fixed to a predetermined portion of the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas ejection port. The positioning member is a short bottomed cylindrical cup member that covers one end side of the filter. By reducing the diameter of the side surfaces of the cup member and the filter together with the housing from the outside, the cup member and the filter are deformed together with the housing, and the filter is fixed to the housing via the cup member. It is characterized by this.

[0008] ( 2 ) The gas generator of the present invention is provided with a gas generating agent that generates gas by burning, includes a filter through which the gas passes inside, and has a long cylindrical housing in which a gas ejection port for ejecting the gas is formed at a position corresponding to the filter, an igniter capable of igniting and burning the gas generating agent, a holder that holds a part of the igniter and is fixed to one axial end of the housing, a closing member fixed to the other axial end of the housing, and a positioning member that contacts the filter inside the housing and can be used to determine the position of the filter. The positioning member has a cylindrical portion having at least a shape that follows the inner wall shape of the housing, and the cylindrical portion is fixed to a predetermined portion of the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas ejection port. The positioning member is a tubular member that is shorter than the axial length of the filter and closes the gas ejection port in the housing. By performing diameter reduction processing from the outside together with the housing at each of the positions on the igniter side of the side surfaces of the tubular member and the filter that are closer to the igniter than the region where the gas ejection port is formed, and at each of the positions on the closing member side of the side surfaces of the tubular member and the filter that are closer to the closing member than the region where the gas ejection port is formed, the tubular member and the filter may be deformed together with the housing, and the filter may be fixed to the housing via the tubular member.

[0011] ( 3 ) The gas generator of the present invention is loaded with a gas generating agent that generates gas by combustion, includes a filter through which the gas passes inside, and has a gas ejection port for ejecting the gas formed at a position corresponding to the filter in a long cylindrical housing, an igniter capable of igniting and burning the gas generating agent, a holder that holds a part of the igniter and is fixed to one axial end of the housing, a closing member fixed to the other axial end of the housing, and a positioning member that contacts the filter in the housing and can be used to determine the position of the filter. The positioning member has at least a cylindrical portion having a shape following the inner wall shape of the housing, and the cylindrical portion is fixed to a predetermined portion of the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas ejection port. The positioning member is a long bottomed cylindrical member having a cylindrical side portion that closes the gas outlet in the housing and a bottom surface portion that closes the other end side of the filter. By reducing the diameter from the outside together with the housing at a position on the igniter side rather than the region where the gas outlet is formed among the side portions of the bottomed cylindrical member and the filter, the bottomed cylindrical member and the filter are deformed together with the housing, and the filter is fixed to the housing via the bottomed cylindrical member. It may also be 。

[0012] ( 4 ) In the gas generator of the above ([[]] 3 [[]]), the closing member is disposed and positioned such that one end side contacts the bottom surface portion of the bottomed cylindrical member in the housing. By reducing the diameter of the housing at the other end side so as to push the closing member toward the filter side, it is preferable that the closing member is a member fixed between the housing and the filter.

[0013] ( 5 ) The cup member of the above ([[]] 1 [[]]), the tubular member of the above ([[]] 2 [[]]), or the bottomed cylindrical member of the above ([[]] 3 [[]]) is preferably made of a resin member or a composite reinforcing member containing resin.

[0014] ( 6 ) The filter of the above ([[]] 2 [[]]) or ([[]] 3 [[]]) is preferably formed in a cylindrical shape having a space at the center portion, and the gas generating agent is also loaded in the space.

Advantages of the Invention

[0015] According to the present invention, it is possible to provide a gas generator that is lighter than before and has cost reduction due to simplification of parts.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Best Mode for Carrying Out the Invention

[0017] <First Embodiment> Hereinafter, with reference to FIGS. 1 and 2, the internal structure of a cylinder-type gas generator according to an embodiment of the present invention will be described.

[0018] (Configuration of Gas Generator 100) The gas generator 100 has an elongated substantially cylindrical outer shape, and includes a housing 10, a holder 20 attached to one open end of the housing 10, and a closing member 12 attached to the other end of the housing 10 so as to close the other open end of the housing 10.

[0019] The housing 10 has peripheral walls 10a, 10b, 10e and is formed of an elongated cylindrical member having openings at both axial ends. The closing member 12 is formed of a disk-shaped member having a predetermined thickness, and has an annular groove portion 13 for caulking (an example of a diameter reduction processing method) fixation described later on its peripheral surface. This annular groove portion 13 for caulking fixation is formed so as to extend in the circumferential direction on the peripheral surface of the closing member 12. Further, a gas ejection port 11 is provided on the peripheral wall near the end of the housing 10 on the side where the closing member 12 is attached. This gas ejection port 11 is a hole for ejecting the gas generated inside the gas generator 100 to the outside, and a plurality of them are provided along the circumferential direction and the axial direction of the housing 10.

[0020] Further, the closing member 12 is made of a metal such as stainless steel, steel, aluminum alloy, or stainless alloy. As shown in FIGS. 1 and 2, with a part of the closing member 12 inserted into one open end of the housing 10, the peripheral wall 10a of the housing 10 corresponding to a part of the peripheral surface of the closing member 12 is reduced in diameter (caulked) inward in the radial direction to form the annular groove portion 13, whereby the closing member 12 is caulked and fixed to the housing 10.

[0021] The holder 20 is made of a metal such as stainless steel, steel, aluminum alloy, or stainless alloy, and has a tapered fitting portion 23 into which the igniter 50 is fitted, an annular groove portion 22 formed on the outer peripheral surface so as to extend in the circumferential direction for caulking fixation, and a fitting portion 21 on the side opposite to the holding position of the igniter 50 into which a female connector (not shown) for energizing the igniter 50 can be fitted. Note that the caulking fixation of the holder 20 to the housing 10 is performed by reducing the diameter (caulking) of the peripheral wall 10e of the housing 10 at a portion corresponding to the annular groove portion 22 provided on the outer peripheral surface of the holder 20 and engaging it with the annular groove portion 22.

[0022] As described above, a female connector is formed in the fitting portion 21 of the holder 20. This female connector is a portion to which the male connector of a harness that transmits a signal from a collision detection means provided separately from the gas generator 100 is connected. A retainer 60 is attached to the female connector. This retainer 60 is attached to prevent the cylinder-type gas generator 100 from malfunctioning due to electrostatic discharge or the like during the conveyance of the gas generator 100 or the like, and the contact to its terminal pin 52 is released when the male connector of the harness is inserted into the female connector at the stage of assembling the airbag device.

[0023] As shown in FIG. 1, an igniter 50 as an ignition means for the gas generant 31 is disposed at one axial end portion of the housing 10 (that is, the portion closer to the holder 20). Note that the igniter 50 and the holder 20 that fixes the igniter 50 have a function as an ignition means for generating a flame for burning the granular gas generant 31 described later.

[0024] As shown in FIG. 1, the igniter 50 is held together with a substantially cylindrical member 53 described later while being inserted into the fitting portion 23 of the holder 20. More specifically, the igniter 50 includes a base frame that inserts and holds a pair of terminal pins 52, and a squib cup 51 (cup-shaped member) attached to the base frame. A resistor (bridge wire) is attached to connect the tips of the terminal pins 52 inserted into the squib cup 51, and the squib cup 51 is filled with an ignition charge so as to surround or contact this resistor. Generally, a nichrome wire or the like is used as the resistor, and generally ZPP (zirconium·potassium perchlorate), ZWPP (zirconium·tungsten·potassium perchlorate), lead tricinate, or the like is used as the ignition charge. In addition, the squib cup 51 may be filled with not only the ignition charge but also a transfer charge. As the transfer charge that can be arranged simultaneously with the ignition charge, a composition composed of a metal / oxidizer typified by boron / potassium nitrate, a composition composed of titanium hydride / potassium perchlorate, or a composition composed of boron / 5-aminotetrazole / potassium nitrate / molybdenum trioxide is used.

[0025] When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pins 52. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and upon receiving this heat, the ignition charge starts to burn. The high-temperature flame generated by the combustion ruptures the squib cup 51 that houses the ignition charge. The time from when current starts to flow through the resistor until the igniter 50 operates is 2 milliseconds or less when a nichrome wire is used as the resistor.

[0026] Also, the squib cup 51 is generally made of metal or resin. A substantially cylindrical member 53 that covers portions of the peripheral wall of the squib cup 51 other than the vicinity of the tip is caulked and fixed to the holder 20 by a caulking portion 24 together with the igniter 50. Here, the substantially cylindrical member 53 is a directional member that directs the direction of the flame generated in the igniter 50 toward the cup member 32 (positioning member) side during operation.

[0027] As shown in FIG. 1, in the internal space of the housing 10, a space 10A in which a gas generating agent 31 or the like is sealed and a filter 41 are provided in parallel in the axial direction of the housing 10.

[0028] The gas generating agent 31 is a composition that is ignited by the flame generated by being ignited by an igniter 50 and generates gas by burning. Further, the gas generating agent 31 is generally formed as a molded body containing a fuel, an oxidizing agent, and an additive. As the fuel, for example, triazole derivatives, tetrazole derivatives, guanidine derivatives, azodicarboxamide derivatives, hydrazine derivatives, etc. or combinations thereof are used. Specifically, for example, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, etc. are preferably used. As the oxidizing agent, for example, basic metal nitrates such as basic copper nitrate and basic copper carbonate, perchlorates such as ammonium perchlorate or potassium perchlorate, nitrates containing cations selected from alkali metals, alkaline earth metals, transition metals, and ammonia are used. As the nitrate, for example, sodium nitrate, potassium nitrate, etc. are preferably used. As the additive, a binder, a slag former, a combustion regulator, etc. are mentioned. As the binder, for example, cellulose derivatives such as hydroxypropylmethylcellulose, metal salts of carboxymethylcellulose, organic binders such as stearates, inorganic binders such as synthetic hydrotalcite and acid clay can be preferably used. As the slag former, silicon nitride, silica, acid clay, etc. can be preferably used. As the combustion regulator, metal oxides, ferrosilicon, activated carbon, graphite, etc. can be preferably used.

[0029] As shown in FIG. 1, the spiral spring 35 is formed by spirally winding so as to be similar to a truncated cone shape as a whole in appearance. Further, one end of the spiral spring 35 abuts on the squib cup 51, and the other end formed in a spiral shape abuts on the gas generating agent 31 so as to apply an elastic force to the gas generating agent 31. By this biasing, the gas generating agent 31 is fixed so as to be sandwiched between the spiral spring 35 and the cup member 32 in the housing 10. Further, the spiral spring 35 has a truncated cone shape that expands in diameter from the igniter 50 side to the gas generating agent 31 side as a whole, so that the direction of the flame discharged from the igniter 50 can be easily directed toward the gas generating agent 31 side.

[0030] The cup member 32 (positioning member) is a short bottomed cylindrical member that covers one end side of the filter 41, and includes a cylindrical portion 32a having an annular groove portion 32a1 and a bottom surface portion 32b that closes one end side of the cylindrical portion 32a. Further, the cup member 32 is fixed to the inner wall of the housing 10 by a diameter reduction process described later performed from the outside of the housing 10 so that the arrangement position of the filter 41 can be positioned at a predetermined position (for example, a position facing the gas jet outlet 11 as shown in FIGS. 1 and 2). The cylindrical portion 32a is configured to be short enough not to block the gas jet outlet 11. The bottom surface portion 32b is melted or damaged by the gas generated during operation. The cup member 32 is made of a resin member or a composite reinforcing member containing resin. Examples of this resin member or composite reinforcing member containing resin include, for example, PA6 (polyamide 6) blended with glass fiber, POM (polyacetal, polyoxymethylene), and the like. Note that the cup member 32 may be made of, for example, a metal such as stainless steel or steel, an alloy such as an aluminum alloy or a stainless steel alloy, as a modified example.

[0031] As shown in FIGS. 1 and 2, after the housing 10 is installed with one end of the filter 41 inserted into the cup member 32, the peripheral wall 10b of the housing 10 corresponding to a part of the peripheral surface of the cylindrical portion 32a of the cup member 32 is reduced in diameter (crimped) radially inward to form the annular groove portion 32a1 and the annular groove portion 41b described later, whereby the cup member 32 is crimped and fixed to the housing 10 and the filter 41. Thereby, the generated gas can bypass between the inner wall of the housing 10 and the outer peripheral portion of the filter 41 so as not to leak out of the gas outlet 11, and the sealing property is ensured. That is, the cup member 32 can allow the gas generated on the igniter 50 side in the housing 10 to flow into the filter 41 side through the portion (the portion corresponding to one end of the hollow portion 41a) cracked due to melting or breakage of the bottom surface portion 32b. Note that the position of the above-described crimping and fixing may be any position as long as it corresponds to the peripheral surface of the cylindrical portion 32a of the cup member 32.

[0032] The filter 41 is composed of a cylindrical member having a columnar (e.g., substantially cylindrical, substantially square tubular, etc.) hollow portion 41a at the center. As described above, after being installed in the housing 10 together with the cup member 32, an annular groove portion 41b is formed by the diameter-reducing process. By using the filter 41 composed of a cylindrical member, the flow resistance of the working gas flowing during operation can be kept low, and efficient gas flow is possible. The filter 41 is made of, for example, a wire rod made of a metal such as stainless steel or steel, or a member wound around a wire mesh or pressed by pressing. Specifically, a knitted wire mesh, a plain woven wire mesh, or an aggregate of crimped woven metal wire rods, etc. is used. The filter 41 functions as a cooling means for cooling the gas by taking away the high-temperature heat of the gas when the gas generated in the housing 10 passes through the filter 41, and also functions as a removing means for removing slag and the like contained in the gas. Here, as a modified example of the filter 41, a filter having a labyrinth flow path formed by combining substantially cylindrical or mortar-shaped parts made of metal may be used. Thereby, since the path of the working gas can be changed in various directions, it is possible to cool the gas and remove slag.

[0033] Also, in the above-described embodiment of the present invention, the case where a so-called knitted wire mesh is used as the filter is exemplified. Instead of this, it is also possible to use a product manufactured by winding punching metal or a product manufactured by winding expanded metal. Here, punching metal is a metal plate provided with only openings (that is, no protrusions are provided at the peripheries of the openings) in a plate-shaped metal member, and expanded metal is a plate-shaped metal member provided with openings in a mesh shape by making cuts, for example, in a staggered pattern and expanding this. Even when such punching metal or expanded metal is used instead of the above-described knitted wire mesh, the same effects as those described in the above-described embodiment of the present invention can be obtained.

[0034] Further, in the punching metal and expanded metal described above, a filter made of a laminate is formed by winding a single metal plate-like member. However, the configuration of the filter is not limited to this configuration. That is, each layer may be composed of separate metal plate-like members and combined to form a filter made of a laminate, or a part of a plurality of layers may be formed by winding a single metal plate-like member, and the remaining layers may be formed by winding another single metal plate-like member, and these may be combined to form a filter made of a laminate.

[0035] Next, the operation during the operation of the gas generator 100 described above will be described. When a vehicle equipped with an airbag device incorporating the gas generator 100 in the present embodiment collides, the collision is detected by a collision detection means provided separately in the vehicle, and based on this, the igniter 50 operates. When the igniter 50 operates, the pressure inside the igniter 50 increases due to the combustion of the ignition charge, whereby the tip of the squib cup 51 of the igniter 50 ruptures, and the flame flows out from the tip of the squib cup 51 of the igniter 50 toward the cup member 32 side inside the housing 10.

[0036] The flame flowing in in this way ignites and burns the gas generating agent 31 in the housing 10, generating a large amount of gas. Due to the combustion of the gas generating agent 31, the pressure in the space 10A in the housing 10 increases, and the generated gas cracks by melting or damaging the portion corresponding to the hollow portion 41a in the bottom surface portion 32b of the cup member 32 and flows into the hollow portion 41a. Thereafter, the generated gas is ejected from the gas generator 100 to the outside through the gas ejection port 11 via the filter 41. Since it passes through the filter 41, the generated gas is cooled to a predetermined temperature. Then, the gas ejected from the gas ejection port 11 is guided into the airbag to inflate and deploy the airbag.

[0037] (Main features of the gas generator 100) According to the present embodiment, it is possible to reduce the number of parts and weight compared to the prior art, and to provide a gas generator 100 in which cost reduction is achieved by simplifying the parts. In particular, when the cup member 32 is made of resin, it is possible to further reduce the weight and cost.

[0038] Further, in the present embodiment, the cup member 32, the filter 41, and the housing 10 are all caulked at the positions of the annular groove portion 32a1, the annular groove portion 41b, and the peripheral wall 10b. Therefore, not only can the cup member 32 be caulked and fixed to the housing 10 and the filter 41, but also the generated gas can be prevented from bypassing between the inner wall of the housing 10 and the outer peripheral portion of the filter 41 and leaking out to the gas outlet 11, and the sealing performance of the housing 10 can be ensured.

[0039] Further, by using the bottom surface portion 32b of the cup member 32 as a partition plate, the breaking pressure during operation can be lowered, so that the internal pressure of the housing 10 (space 10A) during combustion can be reduced.

[0040] <Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. In the present embodiment, parts having the same reference numerals as those in the first embodiment up to the last two digits are the same as the parts in the first embodiment, and thus the description may be omitted. Further, in the present embodiment, parts not particularly described are also the same as those in the first embodiment, and thus the description and illustration may be omitted.

[0041] As shown in FIGS. 3 and 4, the gas generator 200 according to the present embodiment is different from the first embodiment in that a long bottomed cylindrical member 133 (positioning member), which has a cylindrical side surface portion 133a that closes the gas outlet 111 in the housing 110 and a bottom surface portion 133b that closes the other end side (closing member 112 side) of the filter 141, is used instead of the cup member 32 in the first embodiment. The bottomed cylindrical member 133 is fixed to the inner wall of the housing 110 by a diameter reduction process described later performed from the outside of the housing 110 so that the arrangement position of the filter 141 can be positioned at a predetermined position (for example, a position facing the gas outlet 111 as shown in FIGS. 3 and 4). Further, the bottomed cylindrical member 133 is made of a resin member or a composite reinforcing member containing resin. Examples of this resin member or composite reinforcing member containing resin include, for example, PA6 (polyamide 6) blended with 30% glass fiber, POM (polyacetal, polyoxymethylene), PA6, etc. Note that the bottomed cylindrical member 133 may be made of, for example, a metal such as stainless steel or steel, an alloy such as an aluminum alloy or a stainless alloy as a modified example.

[0042] Also, as shown in FIGS. 3 and 4, after the gas generator 200 is installed in the housing 110 with the filter 141 inserted into the bottomed cylindrical member 133, the peripheral wall 110b of the housing 110 corresponding to a part of the peripheral surface of the side surface portion 133a of the bottomed cylindrical member 133 is reduced in diameter (crimped) radially inward to form an annular groove portion 133a1 and an annular groove portion 141b, whereby the bottomed cylindrical member 133 is crimp-fixed to the housing 110 and the filter 141, which is also different from the first embodiment. Note that the position of the above-described crimp fixing may be any position as long as it is on the igniter 150 side of the gas outlet 111.

[0043] Also, the gas generator 200 is different from the first embodiment in that the gas generating agent 131 is also loaded in the hollow portion 141a.

[0044] Next, the operation of the gas generator 200 during operation described above will be explained. When a vehicle equipped with an airbag device incorporating the gas generator 200 in the present embodiment collides, the collision is detected by collision detection means provided separately in the vehicle, and based on this, the igniter 150 operates. When the igniter 150 operates, the pressure inside the igniter 150 rises due to the combustion of the ignition charge, whereby the tip of the squib cup 151 of the igniter 150 ruptures, and the flame flows out from the tip of the squib cup 151 of the igniter 150 toward the filter 141 inside the housing 110.

[0045] The flame flowing in thus ignites and burns the gas generating agent 131 in the housing 110, generating a large amount of gas. Due to the combustion of this gas generating agent 131, the pressure in the space 110A in the housing 110 rises, and the generated gas flows into the hollow portion 141a of the filter 141. Subsequently, the generated gas breaks through the portion of the bottomed cylindrical member 133 corresponding to the gas ejection port 111 by gas pressure via the filter 141. After that, although it is ejected from the gas ejection port 111 to the outside of the gas generator 200, since it passes through the filter 141, the generated gas is cooled to a predetermined temperature. Then, the gas ejected from the gas ejection port 111 is guided into the airbag to inflate and deploy the airbag.

[0046] According to the present embodiment, it is possible to reduce the number of parts and weight compared to the prior art, and it is possible to provide a gas generator 200 in which cost reduction is achieved by simplifying the parts. In particular, when the bottomed cylindrical member 133 is made of resin, the weight can be further reduced and the cost can be reduced.

[0047] In addition, in the present embodiment, the bottomed cylindrical member 133, the filter 141, and the housing 110 are all caulked at the positions of the annular groove portion 133a1, the annular groove portion 141b, and the peripheral wall 110b. Therefore, not only can the bottomed cylindrical member 133 be caulked and fixed to the housing 110 and the filter 141, but also the generated gas can be prevented from bypassing between the inner wall of the housing 110 and the outer peripheral portion of the filter 141 and leaking out to the gas ejection port 111, and the sealing property of the housing 110 can be ensured.

[0048] Further, according to the present embodiment, since the gas generating agent 131 is also loaded in the hollow portion 141a, when the housing has the same diameter, the overall length in the axial direction can be made shorter than that of the first embodiment.

[0049] <Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. 5 and 6. In the present embodiment, parts having the same reference numerals as the first two digits of the first embodiment are the same as those of the first embodiment, and thus the description may be omitted. Also, in the present embodiment, parts not particularly described are the same as those of the first embodiment, and thus the description and illustration may be omitted.

[0050] As shown in FIGS. 5 and 6, the gas generator 300 according to this embodiment is different from the second embodiment in that a tubular member 234 (positioning member) that closes the gas outlet 211 is used inside the housing 210 instead of the bottomed cylindrical member 133 in the second embodiment. The tubular member 234 is fixed to the inner wall of the housing 210 by a diameter reduction process described later performed from the outside of the housing 210 so that the arrangement position of the filter 241 can be positioned at a predetermined position (for example, a position facing the gas outlet 211 as shown in FIGS. 5 and 6). Further, the tubular member 234 is made of a resin member or a composite reinforcing member containing resin. Examples of this resin member or composite reinforcing member containing resin include, for example, PA6 (polyamide 6) containing 30% glass fiber, POM (polyacetal, polyoxymethylene), PA6, and the like. As a modification example, the tubular member 234 may be made of a metal such as stainless steel or steel, an alloy such as an aluminum alloy or a stainless alloy.

[0051] Also, as shown in FIGS. 5 and 6, after the gas generator 200 is installed in the housing 210 with the filter 241 inserted into the tubular member 234, the peripheral walls 210b and 210c of the housing 210 corresponding to two locations on the peripheral surface of the tubular member 234 are reduced in diameter (crimped) radially inward to form an annular groove portion 234a1 and an annular groove portion 241b, and an annular groove portion 234a2 and an annular groove portion 241c. In this way, the tubular member 234 is crimp-fixed to the housing 210 and the filter 241, which is also different from the second embodiment. The positions of the above two crimp-fixings may be any position as long as it is outside the region where the gas outlet 211 is formed, that is, a position on the igniter 150 side of the gas outlet 211 formed closest to the igniter 150 side and a position on the closing member 212 side of the gas outlet 211 formed closest to the closing member 212 side.

[0052] According to this embodiment, the same operational effects as those of the second embodiment can be achieved.

[0053] <Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIG. 7. In this embodiment, parts having the same reference numerals as those in the first embodiment up to the last two digits are the same as the parts in the first embodiment, and thus the description thereof may be omitted. Also, in this embodiment, parts not particularly described are the same as those in the first embodiment, and thus the description and illustration thereof may be omitted.

[0054] As shown in FIG. 7, the gas generator according to this embodiment is mainly different from the first embodiment in that a disc-shaped closing member 312 is used instead of the closing member 12 in the first embodiment.

[0055] One end portion (filter 341) side of the closing member 312 is disposed and positioned so as to contact the other end portion of the filter 341 within the housing 310. Further, the method of fixing the closing member 312 to the housing 310 is as follows. The diameter of the housing 310 is reduced (here, caulking is performed) on the other end side of the closing member 312 so that the closing member 312 is pushed into the filter 341 side, and an annular groove portion 310a is formed. Thereby, the closing member 312 is fixed between the housing 310 and the filter 341 by only one step.

[0056] According to this embodiment, the same operational effects as those of the first embodiment can be achieved. Also, since the closing member 312 is fixed between the housing 310 and the filter 341 so as to be pressed against the other end portion of the filter 341, movement of the closing member 312 during attachment can be prevented. As a result, the inner side of the caulked portion of the housing 310 is more likely to bite into the closing member 312, and the caulking fixing strength can be improved as compared with the case of the first embodiment.

[0057] Moreover, according to the present embodiment, since the shape of the closing member 312 can be simplified, costs such as cutting can be reduced. Also, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the first embodiment, the thickness of the closing member 312 can be made thinner. Therefore, compared with the first embodiment, the axial length of the entire gas generator can be shortened and the weight can be reduced. The reason why the thickness of the closing member 312 can be made thinner compared to the closing member 12 of the first embodiment is as follows. In the first embodiment, the annular groove portion 13 is provided in the closing member 12 and caulked and fixed from the outside of the housing 10 to fix the position of the closing member 12 with respect to the housing 10. On the other hand, in the present embodiment, since the filter 341 is fixed by the cup member 332 (positioning member), the position of the closing member 312 is inevitably determined. Therefore, it is possible to perform caulking and fixing only on the outer side in the axial direction of the housing 310 of the closing member 312, and the closing member 312 can be made thinner compared to the closing member 12 of the first embodiment.

[0058] <Fifth Embodiment> Next, the fifth embodiment of the present invention will be described with reference to FIG. 8. In the present embodiment, parts having the same reference numerals as those in the first embodiment up to the last two digits are the same as the parts in the first embodiment, and thus the description may be omitted. Also, in the present embodiment, parts not particularly described are the same as those in the first embodiment, and thus the description and illustration may be omitted.

[0059] As shown in FIG. 8, the gas generator according to the present embodiment is mainly different from the first embodiment in that a disk-shaped closing member 412 having a stepped shape is used instead of the closing member 12 in the first embodiment.

[0060] The blocking member 412 has a first-stage portion 412a and a second-stage portion 412b provided so as to form a stepped shape together with the first-stage portion 412a, and one end portion (filter 441) side is disposed and positioned so as to contact the other end portion of the filter 441 within the housing 410. Further, as a method for fixing the blocking member 412 to the housing 410, it is as follows. The housing 410 is subjected to a diameter reduction process (here, caulking) on the other end side of the first-stage portion 412a of the blocking member 412 so that the blocking member 412 is pushed toward the filter 441 side, and an annular groove portion 410a is formed. Thereby, in only one step, the blocking member 412 is fixed between the housing 410 and the filter 441.

[0061] According to the present embodiment, the same operational effects as those of the fourth embodiment can be achieved. Further, since the blocking member 412 is a disk-shaped member having a stepped shape, it is possible to provide a thickness in the axial direction of the housing 410 as compared with the blocking member 312 of the fourth embodiment, and the blocking member 412 having higher strength than the blocking member 312 can be obtained.

[0062] <Sixth Embodiment> Next, the sixth embodiment of the present invention will be described with reference to FIG. 9. In this embodiment, parts having the same reference numerals as those of the second embodiment up to the last two digits are the same as the parts of the second embodiment, and thus the description may be omitted. Further, in this embodiment, parts not particularly described are also the same as those of the second embodiment, and thus the description and illustration may be omitted.

[0063] As shown in FIG. 9, the gas generator according to the present embodiment is mainly different from the second embodiment in that a disk-shaped blocking member 512 is used instead of the blocking member 112 in the second embodiment.

[0064] The blocking member 512 is disposed and positioned such that one end (filter 541) side contacts the other end of the filter 541 within the housing 510. Further, the method for fixing the blocking member 512 to the housing 510 is as follows. The housing 510 is subjected to a diameter reduction process (here, caulking) on the other end side of the blocking member 512 so as to push the blocking member 512 toward the filter 541 side, thereby forming an annular groove portion 510a. As a result, in only one step, the blocking member 512 is fixed between the housing 510 and the filter 541.

[0065] According to the present embodiment, the same operational effects as those of the second embodiment can be achieved. Further, since the blocking member 512 is fixed between the housing 510 and the filter 541 by being pressed against the bottom surface portion 533b of the bottomed cylindrical member 533, movement of the blocking member 512 during attachment can be prevented. As a result, the inner side of the caulked portion of the housing 510 is more likely to bite into the blocking member 512, and the caulking fixing strength can be improved compared to the case of the second embodiment.

[0066] Further, according to the present embodiment, the shape of the blocking member 512 can be simplified, so that costs such as cutting processing can be reduced. Also, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the second embodiment, the thickness of the blocking member 512 can be reduced. Therefore, compared to the second embodiment, the axial length of the entire gas generator can be shortened and the weight can be reduced.

[0067] <Seventh Embodiment> Next, a seventh embodiment of the present invention will be described with reference to FIG. 10. In this embodiment, parts having the same reference numerals as those of the third embodiment up to the last two digits are the same as the parts of the third embodiment, and thus the description may be omitted. Also, in this embodiment, parts not particularly described are the same as those of the third embodiment, and thus the description and illustration may be omitted.

[0068] As shown in FIG. 10, the gas generator according to this embodiment is mainly different from the third embodiment in that a disc-shaped closing member 612 is used instead of the closing member 212 in the third embodiment.

[0069] One end portion (filter 641) side of the closing member 612 is disposed and positioned so as to contact the other end portion of the filter 641 within the housing 610. Further, the method for fixing the closing member 612 to the housing 610 is as follows. The housing 610 is subjected to a diameter reduction process (here, caulking) at the other end portion side of the closing member 612 so that the closing member 612 is to be pushed into the filter 641 side, thereby forming an annular groove portion 610a. Thereby, in only one step, the closing member 612 is fixed between the housing 610 and the filter 641.

[0070] According to this embodiment, the same operational effects as those of the third embodiment can be achieved. Further, since the closing member 612 is fixed between the housing 610 and the filter 641 so as to be pressed against the other end portion of the filter 641, movement of the closing member 612 during attachment can be prevented. As a result, the inner side of the caulked portion of the housing 610 is more likely to bite into the closing member 612, and the caulking fixing strength can be improved as compared with the case of the third embodiment.

[0071] Further, according to this embodiment, the shape of the closing member 612 can be simplified, so that costs such as cutting processing can be reduced. Also, when the gas generator of this embodiment has the same diameter as the housing of the gas generator of the third embodiment, the thickness of the closing member 612 can be made thinner. Therefore, compared with the third embodiment, the axial length of the entire gas generator can be shortened and the weight can be reduced.

[0072] <Eighth Embodiment> Next, the eighth embodiment of the present invention will be described with reference to FIGS. 11 and 12. In this embodiment, parts having the same reference numerals as those in the first embodiment up to the last two digits are the same as the parts in the first embodiment, and thus the description thereof may be omitted. Also, in this embodiment, parts not particularly described are the same as those in the first embodiment, and thus the description and illustration thereof may be omitted.

[0073] As shown in FIGS. 11 and 12, the gas generator according to this embodiment is mainly different from the first embodiment in that (1) a disk-shaped closing member 712 is used instead of the closing member 12 in the first embodiment, (2) a cup member 732 is used instead of the cup member 32 in the first embodiment, and (3) the AI agent 740 is provided at a substantially central portion on the side of the gas generating agent 731 at the bottom surface portion 732b of the cup member 732.

[0074] One end portion (filter 741) side of the closing member 712 is disposed and positioned so as to contact the other end portion of the filter 741 within the housing 710. Also, the method of fixing the closing member 712 to the housing 710 is as follows. The housing 710 is reduced in diameter (in this case, caulked) at the other end portion side of the closing member 712 so that the closing member 712 is to be pushed into the filter 741 side, thereby forming an annular groove portion 710a. Thereby, the closing member 712 is fixed between the housing 710 and the filter 741 by only one step.

[0075] The cup member 732 is a member made of a material such as metal or alloy that can be used for welding and bonding, and includes a cylindrical portion 732a and a bottom surface portion 732b provided on the other end side of the cylindrical portion 732a. The cylindrical portion 732a is fixed to the housing 710 by welding from the outside at the position of the peripheral wall 710d (welding portion) of the housing 710. Thereby, together with the positioning of the filter 741, it is also possible to position the closing member 712 before the diameter reduction process. Further, the cup member 732 is a bottomed cylindrical bypass prevention member that partitions the housing 10 in the axial direction, and can prevent the generated gas from bypassing between the inner wall of the housing 10 and the outer peripheral portion of the filter 41 and leaking out to the gas ejection port 11.

[0076] The AI agent 740 has an auto-ignition (AI) function that auto-ignites without depending on the operation of the igniter 750. More specifically, since the AI agent 740 auto-ignites at a temperature lower than that of the gas generating agent 731, in the event of a fire or the like occurring in a vehicle equipped with an airbag device in which the gas generator 800 is incorporated, it is possible to prevent the induction of abnormal operation of the gas generator 800 due to external heating.

[0077] According to the present embodiment, the same operational effects as those of the first embodiment can be achieved. Further, since the closing member 712 is fixed between the housing 710 and the filter 741 so as to be pressed against the other end portion of the filter 741, movement of the closing member 712 during attachment can be prevented. As a result, the inner side of the caulked portion of the housing 710 is more likely to bite into the closing member 712, and the caulking fixing strength can be improved compared to the case of the first embodiment.

[0078] In addition, according to the present embodiment, since the shape of the closing member 712 can be simplified, costs such as machining costs can be reduced. Further, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the first embodiment, since the thickness of the closing member 712 can be reduced, compared with the first embodiment, the axial length of the entire gas generator can be shortened and the weight can be reduced.

[0079] <Ninth Embodiment> Next, the ninth embodiment of the present invention will be described with reference to FIGS. 13 and 14. In this embodiment, parts having the same reference numerals as those in the eighth embodiment up to the last two digits are the same as those in the eighth embodiment, and thus the description may be omitted. Further, in this embodiment, parts not particularly described are also the same as those in the eighth embodiment, and thus the description and illustration may be omitted.

[0080] As shown in FIGS. 13 and 14, the gas generator according to the present embodiment is different from the eighth embodiment in that a disk-shaped closing member 812 having a stepped shape is used instead of the closing member 712 in the eighth embodiment.

[0081] The closing member 812 has a first-stage portion 812a and a second-stage portion 812b provided so as to form a stepped shape together with the first-stage portion 812a, and is disposed and positioned such that one end portion (filter 841) side contacts the other end portion of the filter 841 in the housing 810. Further, the method of fixing the closing member 812 to the housing 810 is as follows. The diameter of the housing 810 is reduced (here, caulking) at the other end side of the first-stage portion 812a of the closing member 812 so that the closing member 812 is pushed toward the filter 841 side, and an annular groove portion 810a is formed. Thereby, the closing member 812 is fixed between the housing 810 and the filter 841 in only one step.

[0082] According to this embodiment, the same operational effects as those of the eighth embodiment can be achieved. Further, since the closing member 812 is a disk-shaped member having a stepped shape, it is possible to provide a greater thickness in the axial direction of the housing 810 than the closing member 712 of the eighth embodiment, and the closing member 812 can have a higher strength than the closing member 712.

[0083] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration should not be considered to be limited to these embodiments. The scope of the present invention is defined by the claims rather than the description of the above-described embodiments, and further includes all modifications within the meaning and scope equivalent to the claims.

[0084] For example, in the second and third embodiments, the gas generating agent may not be filled in the hollow portion of the filter.

[0085] Also, in the first to third embodiments, caulking has been described as an example of the method for reducing the diameter of the housing. However, any method that can reduce the diameter of the housing may be used.

[0086] Further, the present invention may be a gas generator formed by appropriately combining the respective configurations shown in the first to ninth embodiments.

Explanation of Reference Numerals

[0087] 10, 110, 210, 310, 410, 510, 610, 710, 810 Housing 10A, 110A, 210A, 710A, 810A Space 10a, 10b, 10e, 110a, 110b, 110e, 210b, 210c, 310a, 310b, 410a, 410b, 510a, 510b, 610a, 610b, 610c, 710a, 710d, 710e, 810a, 810e Peripheral Wall 11, 111, 211, 311, 411, 511, 611, 711, 811 Gas Outlet 12, 112, 212, 312, 412, 512, 612, 712, 812 Blocking member 13, 22, 32a1, 41b, 113, 133a1, 141b, 213, 122, 222, 234a1, 234a2, 241b, 241c, 332a1, 341b, 432a1, 441b, 533a1, 541b, 634a1, 634a2, 641b, 641c, 722, 822 Annular groove part 20, 120, 220, 720, 820 Holder 21, 23, 121, 123, 221, 223, 721, 723, 821, 823 Fitting part 24, 124, 224, 724, 824 Crimping part 31, 131, 231, 331, 431, 531, 631, 731, 831 Gas generating agent 32, 132, 232, 332, 432, 732, 832 Cup member 32a, 332a, 432a, 732a, 832a Cylindrical part 32b, 133b, 332b, 432b, 533b, 732b, 832b Bottom face part 35, 135, 235, 735, 835 Coil spring 41, 141, 241, 341, 441, 541, 641, 741, 841 Filter 41a, 141a, 241a, 341a, 441a, 541a, 641a, 741a, 841a Hollow part 50, 150, 250, 750, 850 Igniter 51, 151, 251, 751, 851 Squib cup 52, 152, 252, 752, 852 Terminal pin 53, 153, 253, 753, 853 Cylindrical member 60, 160, 260, 360, 460 Retainer 100, 200, 300, 700, 800 Gas generator 133, 533 Bottomed cylindrical member 133a, 533a Side face part 234, 634 Tubular member 740 AI agent

Claims

1. A long cylindrical housing filled with a gas generating agent that generates gas by combustion, containing a filter through which the gas passes inside, and having a gas ejection port for ejecting the gas formed at a position corresponding to the filter; An igniter capable of igniting and burning the gas generating agent; A holder that holds a part of the igniter and is fixed to one axial end of the housing; A closing member fixed to the other axial end of the housing; A positioning member that contacts the filter inside the housing and can be used to determine the position of the filter; comprising; The positioning member has at least a cylindrical portion shaped to follow the inner wall shape of the housing; The cylindrical portion is fixed to a predetermined portion of the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas ejection port; The positioning member is a short bottomed cylindrical cup member that covers one end side of the filter; The gas generator is characterized in that the cup member and the filter are deformed together with the housing by diameter reduction processing from the outside of the housing for each side surface of the cup member and the filter, and the filter is fixed to the housing through the cup member.

2. A long cylindrical housing filled with a gas generating agent that generates gas by combustion, containing a filter through which the gas passes inside, and having a gas ejection port for ejecting the gas formed at a position corresponding to the filter; An igniter capable of igniting and burning the gas generating agent; A holder that holds a part of the igniter and is fixed to one axial end of the housing; A closing member fixed to the other axial end of the housing; A positioning member that contacts the filter within the housing and can be used to determine the position of the filter; Comprising; The positioning member has a cylindrical portion with a shape that at least follows the inner wall shape of the housing; The cylindrical portion is fixed to a predetermined location on the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas ejection port; The positioning member is a tubular member that is shorter than the axial length of the filter and closes the gas ejection port within the housing; At a position on the igniter side of each side surface of the tubular member and the filter that is closer to the igniter than the region where the gas ejection port is formed, and at a position on the closing member side of each side surface of the tubular member and the filter that is closer to the closing member than the region where the gas ejection port is formed, by performing diameter reduction processing from the outside together with the housing, the tubular member and the filter are deformed together with the housing, and the filter is fixed to the housing via the tubular member. A gas generator characterized by this. A long cylindrical housing filled with a gas generating agent that generates gas by combustion, containing a filter through which the gas passes, and having a gas ejection port for ejecting the gas formed at a position corresponding to the filter; An igniter capable of igniting and burning the gas generating agent; A holder that holds a part of the igniter and is fixed to one axial end of the housing; A closing member fixed to the other axial end of the housing; A positioning member that contacts the filter within the housing and can be used to determine the position of the filter; Comprising; The positioning member has a cylindrical portion having a shape that at least follows the inner wall shape of the housing. The cylindrical portion is fixed to a predetermined portion of the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas outlet. The positioning member is a long bottomed cylindrical member having a cylindrical side portion that closes the gas outlet in the housing and a bottom surface portion that closes the other end side of the filter. By performing diameter reduction processing from the outside together with the housing at a position on the igniter side rather than the region where the gas outlet is formed among the side portions of the bottomed cylindrical member and the filter, the bottomed cylindrical member and the filter are deformed together with the housing, and the filter is fixed to the housing via the bottomed cylindrical member. A gas generator characterized by this.

4. One end side of the closing member is disposed and positioned so as to contact the bottom surface portion of the bottomed cylindrical member in the housing, and the diameter of the housing is reduced at the other end side so that the closing member is pushed into the filter side, thereby fixing the closing member between the housing and the filter. The gas generator according to claim 3, characterized in that it is a member.

5. The cup member according to claim 1, the tubular member according to claim 2, or the bottomed cylindrical member according to claim 3 is made of a resin member or a composite reinforcing member containing resin. A gas generator characterized by this.

6. The filter is formed in a cylindrical shape having a columnar space in the central portion. The gas generator according to claim 2 or 3, characterized in that the gas generating agent is also loaded into the space.

Images